Cytokinins

Abstrect

Analysis of cytokinins in plant tissues has historically been laborious and time consuming because of the extremely low levels and diverse molecular structures of the cytokinins. The initial anticipation that cytokinins could be quantified by radioimmunoassay of crude plant extracts (1,2) was, unfortunately, not justified. Detailed analysis requires the sample to be well purified and the individual cytokinins to be separated, so that not only is interference in the assay avoided, but also problems associated with differential crossreactivity of individual cytokinins with the antibodies in the immunoassay (3). The (sometimes subtle) differences in the chemical properties of the cytokinin free bases, ribosides, nucleotides, and the O- and N-glucosides enables the ready separation and quantification of the majority of the cytokinins.